My ZX10R came with mismatched tyres, JUST HOW BAD IS THIS?!

I bought my beautiful green Kawasaki ZX10R from a dealer miles away, I did all the HPI and MOT checks and it all looked good. "Hi Mister Motorcycle Dealer, have some money and please bring me the ZX10R on your van"

And it arrived, it it was beautiful and all was well........ except.........
The front tyre is a Michelin Road 5 and the rear is a Bridgestone Battlax S22

Just how different are these and how much does it matter?

The Road 5 is a sports touring tyre, while the S22 is a sports tyre, and this could cause problems.
A sport touring tyre is designed to work across a wide range of weathers, it'll warm up quickly and will grip at lower temperatures than a sports tyre. They generally have a longer life too, whereas a dedicated sports tyre will take longer to warm up as it's designed to grip best when hot... and may not get fully up to temperature in cold conditions.

What this means is my tyres will have different levels of grip available at different times and in different conditions.
This isnt much of a problem as I tootle across Telford getting to work and back, its not even too much of an issue as I travel A-roads or even the M54... I've never noticed nor have I had a 'moment'.

I am confident that if I go steady then I won't have an issue, but this is a sports bike and there will come a warm sunny day where I go out for fun and that'll be when the matching grip will be vital and my life may depend on it.

What if they were a mix a sports touring and sports tyre from the same brand? It'd be the same issues. While they look similar they are built for different jobs.

What if they were both sports tyres but from different brands?
This would make the safe zone of riding bigger for sure, but at ultimate levels of grip there is still danger. Different tyre manufacturers have different ideas of how their tyres work... some will slide a little, give you some warning that you're playing with fire, some will grip that little bit longer but then just let go. It's a safer mix of what I have currently, but still not optimal.

What if I have a Bridgestone S21 on the front and a Bridgestone S22 on the rear?
Slightly better again, but still not optimal. If you are going to have similar but mismatching tyres on your bike, then you'd want the grippier/better tyre on the front wheel.
So again the safety margin is bigger, but there is a risk the front will let go before the rear.

Using the logic of the better tyre on the front, how does this look with regards to my Kawasaki?
When it's cold n wet my front sports touring tyre will warm up better and have more grip, ideal!
But when it gets warm and the pace picks up, a hot S22 will outgrip a warm Road 5. Not ideal.

So what I have are ok for commuting and pootling but beyond that it's a guessing game and it's not worth coming off the bike for.

Is that all we need to worry about mismatching tyres?
Heck no! Both of these tyres are radial construction, we're going to need to look at construction mix'n'match options.

Ian